RGB and CMYK Make Colorful Alphabet Soup

You may remember learning in elementary school that yellow and blue make green. That’s the one that sticks in my mind anyway. Maybe I had a green fixation as a child.

Then I grew up and life got more complicated. Whether you’re talking about life in general or graphics, it doesn’t matter – as you grow, life gets more complicated. We’re here to uncomplicate the world of graphics for you.

In the world of graphics (and therefore desktop publishing), colors are formulated using two different models. Both are necessary because they serve different technologies.

In the print world, colors are made by mixing four basic colors: cyan, magenta, yellow and black – hence, it’s called the CMYK color model. When your print shop talks about “four-color printing,” this is what they are referring to.

In the world of monitors and screens, colors are made by mixing three different colors: red, blue and green – hence the RGB color model. Generally it doesn’t matter whether you’re talking about your computer monitor, your telephone, or a projection screen – they all use the RGB color model.

Why do you care? You care because you want your products and your logo to be the colors you expect them to be – regardless of whether they’re being seen in print material or in digital form. You care because the colors don’t always translate accurately when converting between color models. If you create your image in RGB and place it in your document as an RGB graphic, then allow Word or Acrobat or InDesign or whatever program you’re using to convert the document to CMYK for printing, the color of the most important element on the page (your logo, for example), might appear dull or just slightly off when you receive the printed piece. Likewise, CMYK images may appear different from what you were trying to achieve if you don’t convert them to RGB before creating that screen-based app.

How are images converted? The best tool is an image manipulation program. Our tool of choice is Adobe Photoshop, but there are less expensive options available. It’s not a difficult process when you have the right tools. You can even write scripts to accomplish the job, although we recommend adding human interaction because leaving it all to the software sometimes gives wonky results. Your graphics professional will not only run the script, but then look at the images and manipulate them as needed to keep the colors accurate and the difference between image and shadows in proper balance.

Since the computer screen is an RGB device, how can you know if you have good CMYK images? Good question! You’re really catching on to this stuff! There are two answers to that question. First, monitors need to be calibrated to adjust the visual image to the accurate color models. (Don’t ask me more about the technical aspect of this. I just follow the instructions.) Secondly, operators learn their monitors. I love my monitor. It’s a 24″ monitor that allows me plenty of workspace. Unfortunately, it doesn’t hold color at the edges. So I know the “sweet spot” for color matching.

The point is…be true to your colors – be sure your graphics are formulated using the color model appropriate to your final output. CMYK for print, RGB for viewscreens.